In a heating ventilation and air conditioning unit (HVAC unit) of an air conditioning device mounted in a vehicle, an evaporator, an air mixing damper, a heater core, and the like are sequentially provided from the upstream side in an air flow channel in a unit case. Temperature-regulated air having temperature regulated by those components is selectively blown off by means of a plurality of blow-off mode switching dampers into a chamber from any of a face blow-off channel, a foot blow-off channel, and a defroster blow-off channel that are provided downstream of those components.
In such a HVAC unit, the plurality of blow-off mode switching dampers are provided so as to be turnable by a link mechanism. The link mechanism includes: a lever provided to a rotating shaft of each blow-off mode switching damper; and a turnable ring including a plurality of cam grooves on each of which a pin provided to the lever slides. When the link of the link mechanism is turned by an actuator, each blow-off mode switching damper is turned at predetermined timing, and a face blow-off channel, a foot blow-off channel, and a defroster blow-off channel can thus be selectively opened/closed (see, for example, PTL 1, PTL 2, and PTL 3).
A blow-off mode, in which the temperature-regulated air is blown off into the chamber from the face blow-off channel, the foot blow-off channel, and the defroster blow-off channel, generally includes five blow-off modes of: a face mode in which the temperature-regulated air is blown off from the face blow-off channel; a high level mode in which the temperature-regulated air is blown off from both the face blow-off channel and the foot blow-off channel; a foot mode in which the temperature-regulated air is blown off from the foot blow-off channel; a defroster/foot mode in which the temperature-regulated air is blown off from both the foot blow-off channel and the defroster blow-off channel; and a defroster mode in which the temperature-regulated air is blown off from the defroster blow-off channel. The five blow-off modes can be switched by switching the plurality of blow-off mode switching dampers.